GlaxoSmithKline (NYSE: GSK) is selling its first bonds in pounds since 2008, joining AT&T Inc. in tapping credit markets as the cost to insure corporate debt from default fell from a one-week high.

Companies are raising at least $3.5 billion from bonds today, extending the busiest start to a December for issuance since 2008. The Markit iTraxx Crossover Index of contracts on 50 companies with mostly high-yield credit ratings dropped 10 basis points to 471, after rising to as high as 497 yesterday.

Bond risk eased as German investor confidence rose more than economists estimated and as investors await progress on U.S. budget talks to avert tax increases and spending cuts in January that could lead to a recession.

“This is realistically the last week to get anything done before the year-end break,” said Juan Esteban Valencia, a strategist at Societe Generale SA in Paris. “If the U.S. budget talks break down we’ll see risk aversion rise, but I think most people are expecting the news to be positive sooner or later.”

Glaxo, the U.K.’s biggest drugmaker, is offering benchmark- sized bonds in pounds in two parts that will be used to fund maturing debt and for general corporate purposes, said Sarah Spencer, a spokeswoman for the company in London.

The company sold a total of 1.4 billion pounds ($2.3 billion) of bonds.

The pharmaceutical firm raised 600 million pounds from 15-year notes yielding 108 basis points more than benchmark government debt, and 800 million pounds from 33-year bonds at a spread of 103 basis points, data compiled by Bloomberg show.

The 15-year portion of Glaxo’s offering will yield 108 to 112 basis points more than benchmark government debt, and the 33-year piece will have a spread of 103 to 107 basis points, according to a person with knowledge of the transaction.

‘Duration Junkies’

“I expect demand for the Glaxo deal will be well in excess of the total raised, given the recent interest in new issues,” said Daniel McKernan, head of European and U.K. credit at Scottish Widows Investment Partnership in Edinburgh, who said he may bid for Glaxo’s notes. “The 15-year looks better value but the 33-year will appeal to the duration junkies.”

The yield premium on Glaxo’s existing 700 million pounds ($1.1 billion) of senior 6.375 percent bonds due March 2039 widened 10 basis points to 105, the biggest gap since July 7, data compiled by Bloomberg show.

AT&T Inc., the largest U.S. telephone company, is selling 1 billion euros of bonds due 2032 at a yield of 140 basis points more than the benchmark swap rate, according to people familiar with the deal, who asked not to be named because they’re not authorized to speak on the matter. It’s the Dallas-based company’s second bond sale in euros this year.

GSK operates its North American headquarters in RTP.

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